"use strict";
// 查找字符串 indexOf
var some = "goog ggog study english! lalala";
var study = "english";
if (some.indexOf(study) > -1) {
    console.log("find the english");
}
console.log(some.indexOf(study), some.lastIndexOf(study)); //找不到 则返回 -1
// 截取字符串 indexOf
console.log(some.substring(8), some.substring(8, 16));
// 替换字符串 indexOf
console.log(some.replace('english', 'chinese'));
